Improved methods of suppressing immune rejection of the transplanted organ by the transplant recipient have made organ donation an increasingly feasible medical procedure since the 1970's. Accordingly, the area of organ preservation has grown in conjunction with the increased success rates of organ transplantation.
The science of organ preservation seeks to maintain the donor organ, once it has been removed from the donor, in a viable condition by artificial means. This ex vivo preservation is done to maintain the organ until a recipient is selected and prepared to receive the organ. During preservation, analysis can be performed on the organ to assess its viability for transplantation, or to match an organ with a recipient. The ability to preserve the organ for longer times would improve the success rate of donor organs, and allow organs to reach a broader base of recipients in need. Organ preservation systems also allows for strategies which improve the function of transplants to be performed.
Ex vivo preservation can also be used to preserve an organ for medical research purposes or to pre-treat a transplantable organ to enhance its viability and functionality post-transplantation.
Various prior art patents detail aspects of organ preservation. U.S. Pat. Nos. 5,941,841, 6,027,498, and 5,326,706 describe methods of controlling biological fluid. U.S. Pat. Nos. 6,100,082, 6,673,594, 5,338,662, 3,654,085, 7,176,015, and 5,385,821 describe devices and methods associated with the preservation of organs. Support systems and methods that can be used to repair damage to organs are disclosed in U.S. Pat. Nos. 6,642,045 and 5,843,024. U.S. Pat. No. 5,965,433 discloses a device to oxygenate the perfusate. U.S. Pat. Nos. 7,504,201 and 5,871,464 discuss the preservation of organs for purposes other than organ transplantation. Solutions for preservations of organs or tissues are described in U.S. Pat. Nos. 7,250,292 and 4,879,283.
U.S. Pat. Nos. 5,941,841 and 6,027,498 describe the control of a blood pump flow output during cardiopulmonary bypass to mimic normal pulsatile flow from the heart and control of a ventilator output to mimic normal breathing of healthy lungs. A pattern of variation of time of a biological fluid to an organ of a mammalian species is established. A variable control parameter for regulation of flow of biological fluid to the organ is generated in accordance with the pattern, and the flow of biological fluid to the organ is controlled in accordance with the variable control parameter.
U.S. Pat. No. 5,326,706 discloses a organ preservation system and a method of perfusing the donor organ. Perfusion of the donor organ comprises the use of a pressure sensor to determine the vascular resistance of the organ. The perfusion pump control responds to sensor signals and adjusts the pulse rate accordingly. The pulse rate of the pump is decreased if the resistance of the perfused organ increases, and vice versa.
In U.S. Pat. No. 6,100,082, a perfusion apparatus for maintaining a harvested organ during a preservation period is disclosed. U.S. Pat. No. 6,100,082 teaches an apparatus comprising a preservation chamber, and a perfusion circuit with a line for providing an oxygenated fluid to the organ, and a second line for carrying depleted fluid from the organ. U.S. Pat. Nos. 6,673,594 and 6,977,140 describe an organ perfusion apparatus and method for perfusing an organ that monitors, sustains, and/or restores the viability of the organ, and discloses a transporting or storing apparatus. In U.S. Pat. No. 3,654,085, a pressure chamber for storing organic transplants and supplying the transplants with oxygenated blood is provided with an oxygenator and a blood pump inside the chamber. In U.S. Pat. No. 7,176,015, a chilled oxygenated nutrient solution is perfused in a transportable organ preservation system. U.S. Pat. No. 5,385,821 discloses a method and apparatus for preserving tissue ex vivo. The tissue preservation devices includes a gas permeable membrane and perfusate which oxygenates the tissue.
In U.S. Pat. No. 5,338,662, a device, and methods for perfusing organs by controlling either the perfusion pressure or the perfusate flow rate is disclosed. Devices and methods for perfusing multiple organs simultaneously on the same device are also disclosed.
In U.S. Pat. No. 6,642,045, a metabolic support system for maintaining an organ or tissue at near metabolic rate is disclosed. The support system utilizes a warm perfusion solution. U.S. Pat. No. 5,843,024 discloses a process and a solution for resuscitation to induce repair of is chemically damaged organs and tissues.
U.S. Pat. No. 5,965,433 discloses a perfusion device coupled with an oxygenator module. The perfusion apparatus uses compressed oxygen to push perfusate pumping piston to pump the perfusate through an oxygenator. The piston strokes are in an arrangement to allow for continuous supply of oxygen to the oxygenator, while slowly discharging perfusate through the oxygenator.
U.S. Pat. No. 7,504,201 discloses a method for perfusing an organ to preserve the organ in order to perform further studies on, or with the organ. An organ is perfused with a first medical fluid, and then a second medical fluid to introduce a substance into the organ to create a reaction between the organ and the substance. U.S. Pat. No. 5,871,464 discusses the delivery of a viral vector gene therapy pharmaceutical to ex vivo tissue.
In U.S. Pat. No. 7,250,292, the use of a hypertonic solution to reduce injury to tissue that is caused by cooling and warming of tissue is disclosed. The hypertonic solution is used prior to preservation cooling of tissue. U.S. Pat. No. 4,879,283 describes a solution for the preservation of organs using a perfusate or storage solution containing a specific synthetic hydroxyethyl starch in place of human serum albumin.
Each of the foregoing patents is hereby incorporated by reference except where the teaching is inconsistent with the present disclosure.
The present inventor has recognized that known prior art organ preservation systems have been disadvantageous for various reasons. Prior art organ preservation systems lack a versatility that allows the user to accommodate various types of organs, for purposes of both organ preservation for transplantation and for medical research. Prior art systems also do not provide organ preservation devices which can be used to perfuse the donor, or allow a donor to benefit from the functionality of an ex vivo organ that may not be suitable for transplantation.
The present inventor has recognized that prior art systems lack a compact design and efficiency. Prior art configurations do not incorporate an oxygenator with the heat exchanger as in the present invention. The present inventor recognizes a need for a compact system that is easy to use and maintain. The present inventor further recognizes a need for a system that utilizes autoclave sterilizable parts that can be reused, thus reducing the costs associated with organ preservation.